This article links to an uncritical report on the controversial GFAJ-1 finding, which is widely considered to be erroneous:
https://en.wikipedia.org/wiki/GFAJ-1#Criticism
Why should I believe it's correct this time?
https://en.wikipedia.org/wiki/GFAJ-1#Criticism
Why should I believe it's correct this time?
The paper (indirectly) cited here is claiming that some micro-organisms use simple Arsenic-containing ions for electron transport as part of their metabolic cycles. This is a much less outrageous claim and, I think, already documented in high-Arsenic environments. The only big deal here is, I believe, that this is a low-Arsenic environment.
Original paper: http://sci-hub.tw/https://doi.org/10.1073/pnas.1818349116